Story last updated at 10/28/2009 - 12:18 pm
Alaska's fishing industry will soon know if more restrictions might be imposed to protect sea lions in prime fishing grounds. In mid-November federal fishery scientists will unveil a draft biological opinion (BiOp) on proposed changes to existing rules for fishing fleets in portions of the Gulf of Alaska, Aleutian Islands and Bering Sea.
When Western Alaska stocks of Steller sea lions were listed as a threatened species in 1990, it forced widespread restrictions on where and when boats could fish. Fleets were displaced from three to up to 20 miles from haul-outs, rookeries or other critical habitat for sea lions. By law, managers were required to craft a plan to aid in the animals' recovery.
The BiOp will incorporate all new research from the past five years, said Doug DeMaster, director of the Alaska Fisheries Science Center in Juneau.
"Overall, the numbers from 2000 to 2008 show there is not a strong trend, and in fact, there is the appearance of a sea lion increase. We're waiting for the 2009 census data to make sure we're interpreting that apparent increase correctly," DeMaster said. Based on 2004-2005 data, the total population of western Steller sea lions in Alaska is estimated to be approximately 45,000 animals.
"In terms of a BiOp, juvenile survival appears to be sufficiently high, as well as adult survival," he added. "The factor that seems to be problematic right now is the reproductive rate of adult females at the age of sexual maturity. So it's the reproductive side of the equation that seems to be preventing recovery."
Scientists also are factoring in the role killer whales play in preventing sea lion recovery.
"I think most of us have thought for a long time that killer whales and predation is an important source of sea lion mortality," DeMaster said.
That theory gained more credence this month when a tagging study indicated that four out of five sea lions suffered sudden, traumatic deaths, most likely from killer whales. Since 2005 researchers at Oregon State University (OSU) have partnered with the Alaska Sea Life Center in Seward to implant lifelong tags in the body cavities of 27 captured and released sea lions. The tags - developed by Wildlife Computers of Redmond, Wash. - record body temperature and other internal data. Team leader Markus Horning said researchers can tell if a sea lion died suddenly by its internal temperature changes and by the tag's immediate or delayed transmissions.
Horning admitted that identifying the actual predators is a bit of guesswork, but said only a couple of species are known to prey on sea lions and are common in the region of Alaska where the five tags went off. He said in an OSU release that "if the proportion of sea lions killed by predation in this study was applied to population models, more than half of the female Steller sea lions would be consumed by predators before they have a chance to reproduce."
Horning called the study a "wake-up call" for managers to begin looking more closely at the role of predation as a determinant in Steller sea lion populations.
Meanwhile, Doug DeMaster said there are basically four different possibilities that could be expressed in the draft BiOp as to whether or not fisheries adversely impact sea lions: no jeopardy and no adverse modification, jeopardy but no adverse modification, no jeopardy and adverse modification, or there could be both.
The BiOp will be presented to the North Pacific Fishery Management Council in December. Any new fishing rules would go into effect in 2010.
Lots of good fish stories get lost in the daily news shuffle - here's a sampler from last week:
- Alaska salmon ranks as a "super green" seafood on the popular Monterey Bay Aquarium list of best consumer choices. Alaska line-caught cod also made the list. The aquarium has distributed 32 million wallet-size Seafood Watch lists over 10 years.
- Russia's salmon haul this year was the biggest in 100 years, topping 550-thousand tons, or 1.2 billion pounds. Blame that for the price slash by half for pink salmon roe from Alaska.
- The Pacific hake fishery has merited an ok by the international Marine Stewardship Council as a sustainably managed fishery. Hake, or whiting, has the most tonnage on the west coast and Canada; outside of Alaska.
- Researchers at Duke University have unlocked the secret of barnacle "glue." Amazingly, the glue binds together exactly the same way as human blood does when it clots. The scientists hope more research might lead to a non-toxic solution for marine fouling, where barnacles stick to boat hulls creating drag.
- The Irish Times reports that scientists are testing chitin extracts from crab and shrimp shells to treat obesity. Experiments show that chitin interferes with the uptake of fats into cells, and blocks the body's hunger response. Ireland also is testing 500 local species of sea weeds for its untapped bioactive potential in weight loss and other health uses. In Japan, the sea weed or "sea vegetable" industry is valued at $700 million a year.
- Nippon Suisan, parent company of Unisea and Gortons Seafoods, plans to market fish oil made from orange roughy skins for use in moisturizing creams. The oil is said to have tremendous moisture retaining properties, and the company expects sales to cosmetic makers will top $3 million the first year.
American Seafoods Company is again accepting applications for its Alaska community grant program. In early December the company's advisory board will donate funds totaling $30,000 to projects that address issues such as hunger relief, housing, education, research and cultural activities. Deadline to apply is Nov. 16. Applications are online at http://www.americanseafoods.com. E-mail questions to firstname.lastname@example.org or call 206-256-2659.
Laine Welch has been covering news of Alaska's seafood industry since 1988. Her weekly Fish Factor column appears in a dozen newspapers and web outlets. Her daily Fish Radio programs air on 27 stations around Alaska. Welch lives in Kodiak.